--- a/arch/x86/Makefile
+++ b/arch/x86/Makefile
@@ -124,6 +124,10 @@ core-y += $(fcore-y)
 # Xen paravirtualization support
 core-$(CONFIG_XEN) += arch/x86/xen/
 
+# RDC R-321X support
+cflags-$(CONFIG_X86_RDC321X)  := -Iarch/x86/include/asm/mach-rdc321x
+core-$(CONFIG_X86_RDC321X)   += arch/x86/mach-rdc321x/
+
 # lguest paravirtualization support
 core-$(CONFIG_LGUEST_GUEST) += arch/x86/lguest/